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| #include <bits/stdc++.h>
#define MOD 201314
#define MAXN 50005
using namespace std;
inline int read(){
int x=0,f=1;
char ch=getchar();
while (ch<'0'||ch>'9'){
if (ch=='-') f=-1;
ch=getchar();
}
while (ch>='0'&&ch<='9'){
x=(x<<3)+(x<<1)+(ch^'0');
ch=getchar();
}
return x*f;
}
vector<int>G[MAXN];
inline void AddEdge(int u,int v){
G[u].push_back(v);
}
int sz[MAXN],big[MAXN],fa[MAXN],top[MAXN],dep[MAXN];
void dfs1(int u){
sz[u]=1;
for (register int i=0;i<G[u].size();++i){
int v=G[u][i];
if (v!=fa[u]){
dep[v]=dep[u]+1;
dfs1(v);
sz[u]+=sz[v];
if (sz[big[u]]<sz[v]) big[u]=v;
}
}
}
int seq[MAXN],cnt;
void dfs2(int u,int t){
seq[u]=++cnt;
top[u]=t;
if (big[u]) dfs2(big[u],t);
for (register int i=0;i<G[u].size();++i){
int v=G[u][i];
if (v!=fa[u]&&v!=big[u]){
dfs2(v,v);
}
}
}
namespace SegmentTree{
struct node{
int l,r;
int val,tag;
inline int len(){return r-l+1;}
}tree[MAXN<<2];
#define lc i<<1
#define rc i<<1|1
inline void Change(int i,int v){
tree[i].val=(tree[i].val+v*tree[i].len()%MOD)%MOD;
tree[i].tag=(tree[i].tag+v)%MOD;
}
inline void pushdown(int i){
if (tree[i].tag){
Change(lc,tree[i].tag),Change(rc,tree[i].tag);
tree[i].tag=0;
}
}
inline void pushup(int i){
tree[i].val=(tree[lc].val+tree[rc].val)%MOD;
}
void Build(int i,int l,int r){
tree[i].l=l,tree[i].r=r;
tree[i].val=tree[i].tag=0;
if (l==r) return ;
int mid=(l+r)>>1;
Build(lc,l,mid);
Build(rc,mid+1,r);
}
void Update(int i,int L,int R,int val){
if (L<=tree[i].l&&tree[i].r<=R){
Change(i,val);
return ;
}
int mid=(tree[i].l+tree[i].r)>>1;
pushdown(i);
if (L<=mid) Update(lc,L,R,val);
if (mid<R) Update(rc,L,R,val);
pushup(i);
}
int Query(int i,int L,int R){
if (L<=tree[i].l&&tree[i].r<=R){
return tree[i].val;
}
int mid=(tree[i].l+tree[i].r)>>1,ans=0;
pushdown(i);
if (L<=mid) ans=(ans+Query(lc,L,R))%MOD;
if (mid<R) ans=(ans+Query(rc,L,R))%MOD;
return ans;
}
}
using namespace SegmentTree;
inline void Update_Chain(int u,int v){
while (top[u]!=top[v]){
if (dep[top[u]]<dep[top[v]]){
swap(u,v);
}
Update(1,seq[top[u]],seq[u],1);
u=fa[top[u]];
}
if (dep[u]>dep[v]) swap(u,v);
Update(1,seq[u],seq[v],1);
}
inline int Query_Chain(int u,int v){
int ans=0;
while (top[u]!=top[v]){
if (dep[top[u]]<dep[top[v]]){
swap(u,v);
}
ans=(ans+Query(1,seq[top[u]],seq[u]))%MOD;
u=fa[top[u]];
}
if (dep[u]>dep[v]) swap(u,v);
return (ans+Query(1,seq[u],seq[v]))%MOD;
}
int n;
inline void Init(){
dep[1]=1;
dfs1(1);
dfs2(1,1);
Build(1,1,n);
}
struct Q{
int pos,flag,z,id;
}q[MAXN<<2];
int ans[MAXN];
inline bool operator < (const Q &A,const Q &B){
return A.pos<B.pos;
}
int tot;
int main(){
n=read();int m=read();
for (register int i=2;i<=n;++i){
int f=read()+1;
fa[i]=f;
AddEdge(f,i);
}
Init();
for (register int i=1;i<=m;++i){
int l=read(),r=read()+1,z=read()+1;
q[++tot]=Q{l,-1,z,i};
q[++tot]=Q{r,1,z,i};
}
sort(q+1,q+1+tot);
int now=0;
for (register int i=1;i<=tot;++i){
while (now<q[i].pos){
Update_Chain(1,++now);
}
ans[q[i].id]+=Query_Chain(1,q[i].z)*q[i].flag;
}
for (register int i=1;i<=m;++i){
printf("%d\n",(ans[i]+MOD)%MOD);
}
}
|
